Data-signaling apparatus for well drilling tools

ABSTRACT

In the preferred embodiments of the invention disclosed herein, a well tool having new and improved data-signaling apparatus and carrying a drill bit on its lower end is dependently coupled from a drill string and lowered into a borehole being excavated. During the drilling operation, measurements are successively made of selected borehole conditions, formation properties, or the like, which are converted by the data-signaling apparatus into coded electrical signal for repetitively initiating the operation of a valve of unique design operatively arranged on the tool to be selectively actuated by the drilling fluid interrupting the flow of the drilling fluid being circulated through the drill string. In this manner, the valve functions to produce a series of encoded pressure pulses in the drilling fluid which are representative of the measurements being obtained. These pressure pulses are transmitted through the drilling fluid to the surface where they are sensed and converted into meaningful indications of the measurements.

United States Patent Claycomb DATA-SIGNALING APPARATUS FOR WELL DRILLINGTOOLS Primary Examiner- Benjamin A. Borchelt Assistant ExaminerN.Moskowitz Attorney-Ernest R. Archambeau, Jr., Stewart F.

Moore, David L. Moseley, Edward M. Roneyand Wil- I liam R. Sherman [57]ABSTRACT In the preferred embodiments of the invention disclosed herein,a well tool having new and improved data-signaling apparatus andcarrying a drill bit on its lower end is dependently coupled from adrill string and lowered into a borehole being excavated. During thedrilling operation, measurements are successively made of selectedborehole conditions, formation properties, or the like, which areconverted by the datasignaling apparatus into coded electrical signalfor repetitively initiating the operation of a valve of unique designopcratively arranged on the tool to be selectively actuated by thedrilling fluid interrupting the flow of the drilling fluid beingcirculated through the drill string. In this manner, the valve functionsto produce a series of encoded pressure pulses in the drilling fluidwhich are representative of the measurements being obtained. Thesepressure pulses are transmitted through the drilling fluid to thesurface where they are sensed and converted into meaningful indicationsof the measurements.

12 Claims, 10 Drawing Figures 1 a a ifs-1% MEASURING DEVICES A TTORNEYDATA-SIGNALING APPARATUS FOR WELL DRILLING TOOLS Those skilled in theart have, of course, long recognized the benefits of obtaining variousmeasurements at the bottom of a borehole during the course of a drillingoperation. For instance, such information as the weight on the drillbit, the drill string torque, the inclination and the azimuthaldirection of the borehole, bottom hole pressures and temperatures aswell as various characteristics of the formations being penetrated areall measurements of significant interest.

Various proposals have, of course, been made heretofore for transmittingsuch measurements from the bottom of a borehole to the surface. Of themany different tools proposed, perhaps the most promising of all utilizea condition-responsive valve for selectively interrupting the flow ofthe circulating drilling fluid in a predetermined coded sequencerepresentative of the measurements to produce a series of momentarypressure surges which are successively transmitted through the drillingfluid to the surface for detection by appropriate sensing devices. Theseproposed tools have, therefore, generally employed a typicalsolenoidoperated valve which is coupled to one or more condition-sensingdevices by means of appropriate electronic circuitry operativelyarranged for opening and closing the valve in accordance with this codedsequence.

For various reasons, however, these prior proposals have generally beenconsidered to be unacceptable for commercial drilling operations. Forinstance, since the signaling valves in such prior tools havecustomarily been directly operated by solenoids, the mechanical forcesrequired just for operating these solenoids become excessive in evenrelatively shallow wells. Moreover, by virtue of their substantial powerrequirements, the physical size of such solenoids make them impracticalfor the usual sizes of drilling tools.

Accordingly, it is an object of the present invention to provide new andimproved data-signaling apparatus for use with well-drilling tools andwhich is specially adapted for rapidly transmitting downholemeasurements to the surface with minimum electrical requirements.

This and other objects of the present invention are attained byproviding a well tool adapted to be connected in a drill string having adrill bit dependently coupled thereto for excavating a borehole as adrilling fluid is circulated through the drill string and a fluidpassage arranged in the tool. Data-signaling means are arranged on thetool and include condition-measuring means which are coupled tomeasurement-encoding means adapted for producing coded electricalsignals indicative of one or more selected downhole conditions which maybe experienced during the course of a drilling operation. To generatedistinctive pressure pulses in the circulating drilling fluidrepresentative of such measurements, the measurement-encoding meansoperatively drive pressure-signaling means arranged on the tool andincluding valve means adapted to momentarily block or close the fluidpassage for developing each pressure pulse. Biasing means areoperatively arranged for returning the valve means to a passageopeningposition to await the next electrical signal. The pressure-signalingmeans further include an actuator which, in response to the electricalsignals produced by the measurement-encoding means, only initiates theoperation of the valve means. Means are operatively associated with thevalve means and adapted for utilizing the circulating drilling fluid asa motive force to positively operate the valve means as well as toenergize the biasing means each time the actuator is operated.

The novel features of the present invention are set forth withparticularity in the appended claims. The invention, together withfurther objects and advantages thereof, may be best understood by way ofthe following description of exemplary apparatus employing theprinciples of the invention as illustrated in the accompanying drawings,in which:

FIG. 1 shows a well too] arranged in accordance with the presentinvention as it will appear while coupled in a drill string during thecourse of a typical drilling operation;

FIG. 2 is a schematic representation of a preferred embodiment of thetool shown in FIG. 1;

FIGS. 3-5 schematically depict certain successive operating positions ofa preferred embodiment of datasignaling apparatus incorporating theprinciples of the present invention;

FIG. 6 illustrates an alternative arrangement of one portion of the newand improved data-signaling apparatus shown in FIGS. 3-5; and

FIGS. 7-10 respectively shown the successive operating positions ofother data-signaling apparatus of a similar nature and which alsoincorporates the broader principles of the present invention.

Turning now to FIG. 1, a new and improved well tool 10 arranged inaccordance with the present invention is depicted coupled in a typicaldrill string 1 1 having a rotary drill bit 12 dependently coupledthereto and adapted for excavating a borehole 13 through various earthformations as at 14. As the drill string 11 is rotated by a typicaldrilling rig (not shown) at the surface, substantial volumes of adrilling fluid or so-called mud are continuously pumped downwardlythrough the tubular drill string and discharged from the drill bit 12 tocool the bit as well as to carry earth borings removed by the bit to thesurface as the mud is returned upwardly along the borehole l3 exteriorof the drill string. As is typical, the mud stream is circulated byemploying one or more high-pressure mud pumps (not shown) whichcontinuously draw the fluid from a storage pit or vessel for subsequentrecirculation by the mud pumps. It will be appreciated, therefore, thatthe constantly circulating mud stream flowing through the drill string 11 serves as a transmission media that is well suited for transmittingpressure surges or pulses to the surface.

In accordance with the principles of the present invention,data-signaling means 15 are arranged on the well tool 10 and includecondition-measuring means 16 such as one or more condition-responsivedevices, as at 17 and 18, which are coupled to an appropriatemeasurement encoder l9 operatively arranged to produce a series of codedelectrical signals that are representative of the measurements beingobtained by the condition-responsive devices. Pressure-signaling means20 coupled to the encoder 19 are operatively arranged to respond tothese coded signals for selectively generating a corresponding series ofpressure pulses in the circulating fluid by momentarily and rapidlyinterrupting the flow of the drilling fluid through the drill string II.It will be appreciated, of course, that these transitory pressure pulsesor surges will be similar to those caused by a so-called water hammer.Thus, these pressure waves will be transmitted to the surface by way ofthe mud stream flowing within the drill string 11 and at the speed ofsound in the particular drilling fluid. Ac-

- cordingly, as will subsequently be explained in greater detail, thepressure-signaling means produce these pressure pulses-to provideencoded representations or data indicative of the one or more downholeconditions sensed by the condition-measuring devices 17 and 18. Thisdata is, in turn, successively transmitted to the surface in the form ofthese pressure pulses for detection and conversion into meaningfulindications or records by suitable surface-located pressure-transducingapparatus 21 such as those disclosed in either US. Pat. No. 3,488,629 orUS. Pat. No. 3,555,504.

Turning now to FIG. 2, a schematic view is shown of the new and improvedwell tool 10 just prior to the production of a pressure surge or pulsewhich is to be transmitted to the surface by way of the drilling fluidbeing circulated through the drill string 11. As illustrated, the welltool 10 is comprised of an elongated tubular member 22 that is coaxiallyarranged within a thick-wall tubular housing 23 which is tandemlycoupled in the drill string 11 just above the drill bit 12.

I Although the inner member 22 could just as well be permanently mountedin the housing 23, it is preferred to adapt the inner member forselective retrieval to the surface by way of the drill string 11. Tofacilitate this, the inner bore 24 of the tubular housing 23 is reducedto provide an annular shoulder 25 on which the lower end of the tubularmember 22 is cooperatively seated and releasably latched to the housingby means such as one or more inwardly contractible latch fingers 26having outwardly enlarged heads as at 27 which are dependently arrangedon the inner member and adapted to contract as they pass through theannular shoulder and then spring outwardly again to secure the innermember in its depicted position. Upright collet fingers 28 havinginwardly directed shoulders 29 are mounted on the upper end of the innertubular member 22 and cooperatively arranged for receiving aconventional wireline grapple or overshot (not shown) adapted for beingcoupled therewith to permit the inner member to be retrieved to thesurface through the drill string 11.

Although a self-contained power supply could be employed, it ispreferred to utilize the flowing mud stream as a motivating source forgenerating electrical power for operation of the new and improved welltool 10. Accordingly, in the preferred manner of accomplishing this, areaction turbine 30 is journalled, as by a bearing 31, to the upper endof the inner member 22 and operatively arranged to be rotatively drivenby the downwardly flowing drilling fluid for driving a generator 32coupled to the turbine by an elongated shaft 33. To facilitate theoperation of the turbine 30, the inner bore 24 of the outer housing 23is enlarged to provide an annular cavity or chamber 34 into which themud stream will be discharged from the outlet ports 35 of the turbine.One or more longitudinal passages, as at 36, are formed in the outerhousing 22 for conducting the mud stream from the upper chamber 34 toanother chamber 37 formed therebelow in an intermediate portion of theouter housing. It will be appreciated, therefore, that during theoperation of the well tool 10, the circulation of the drilling fluid ormud will be effective for continuously driving the turbine 30 and thegenerator 32 coupled thereto to produce electrical power for operatingthe data-signaling means 15.

As depicted in FIG. 3, at least a substantial portion of the mud streamleaving the intermediate chamber 37 enters one or more downwardlyinclined lateral ports 38 formed at an intermediate location in theinner member 22 and is directed thereby through an annular valve seat 39coaxially arranged within the longitudinal bore 40 of the inner memberand just below the ports on through the lower portion of the innertubular member. To produce the aforementioned pressure pulses, thepressure-signaling means 20 include an annular valve member 41 which isslidably arranged in the longitudinal bore 40 of the inner member 22 andadapted for reciprocating movement therein between an elevated positionjust above the fluid ports 38 and a lower port-closing position over theports where the valve member is cooperatively received within the valveseat 39. To prevent unbalanced longitudinally acting pressure forcesfrom retarding the upward and downward movements of the valve member 41,one or more longitudinal passages 42 are arranged through the valvemember. Accordingly, it will be recognized that so long as the valvemember 41 remains in its elevated position depicted in FIG. 3, thedrilling fluid can freely circulate from the chamber 37 through thelateral ports 38 and the valve seat 39 and pass without significantrestriction on through the lower portion of the longitudinal bore 40 tothe drill bit 12 therebelow. On the other hand, it will be appreciatedthat downward movement of the valve member 41 into the valve seat 39will momentarily at least block or close the fluid ports 38 and producea corresponding pressure surge or pulse which will be transmitted backup the mud stream in the drill string 11 for detection at the surface.

To actuate the valve member 41, the pressure-signaling means 20 furtherinclude an elongated rod 43 which is coaxially arranged within anupright tubular extension 44 secured to the valve member and adapted forsliding axial movement in relation thereto. The lower end of theelongated rod 43 is enlarged, as at 45, to provide a head adapted toclosely fit within the longitudinal bore 40 below the valve seat 39 aswell as to define an upwardly directed surface 46 which, in the elevatedposition of the slidable rod depicted in FIG. 3, is located just abovethe flow path of the drilling fluid passing through the lateral ports38. To further assure that the upper surface 46 of the enlarged head 45is out of the flow path of the drilling fluid, the lower end of thevalve member 41 is counterbored, as at 47, for complementally receivingthe uppermost portion of the head.

It will be appreciated from FIG. 4, however, that a limited downwardmovement of the slidable rod 43 in relation to the valve member 41 willposition the upwardly directed surface 46 at least partially in the mainflow path of the drilling fluid passing through the ports 38. Thus, theimpingement of the drilling fluid on the surface 46 will be effectivefor shifting the elongated rod 43 further downwardly in relation to theports 38 and the valve member 41 to position the head 45 within thelongitudinal bore 40 below the valve seat 39. This downward movement ofthe elongated rod 43 will also bring an enlarged shoulder 48 arrangedthereon downwardly into engagement with an enlarged head 49 formed onthe upper end of the tubular extension 44 of the valve member 41.

Accordingly, once the rod 43 has moved downwardly a sufficient distanceto engage the shoulder 48 with the enlarged head 49, continued downwardtravel of the elongated rod will be effective for shifting the valvemember 41 downwardly to its port-blocking position within the valve seat39 to halt further flow of the drilling fluid through the ports 38. Itwill be appreciated, therefore, that the initial downward travel of theelongated rod 43 is readily accomplished by the impingement of thedrilling fluid on the surface 46 as the fluid passes through the ports38. Moreover, once the lower enlarged head 45 has been moved into thelongitudinal bore 40 as depicted in FIG. 4, the flow of the drillingfluid will be sufflciently interrupted to produce a pressure surge whichis effective for carrying the rod 43 further downwardly to positivelyshift the valve member 41 to its port-closing position (FIG. 5) byvirtue of the pressure forces acting downwardly on the surface 46.

To return the elongated rod 43 and the valve member 41 to their elevatedpositions after the valve member has been closed, biasing means areprovided such as a relatively stout compression spring 50 which iscoaxially arranged around the upper portion of the rod and supported onan inwardly directed shoulder 51 formed on the inner member 22. A cuppedring 52 is coaxially arranged around the elongated rod 43 and slidablypositioned between the upper end of the spring 50 and the lower surfaceof an inwardly directed shoulder 53 arranged within the inner member 22above the shoulder 51. In this manner, by arranging an outwardlydirected shoulder 54 on the elongated rod 43 to be normally spacedslightly above the slidable ring 52, the initial downward travel of theelongated rod 43 will be effective for bringing the shoulder 54 intoengagement with the ring so as to then compress the spring 50 uponfurther downward travel of the rod. A light spring 55 is mounted betweenthe cup-shaped ring 52 and the shoulder 54 thereabove to normallyposition the enlarged head 45 in the counterbore 47.

Biasing means such as a relatively weak compression spring 56 arearranged around the tubular extension 44 between an inwardly-directedshoulder 57 on the inner member 22 below the shoulder 51 and theenlarged head 49 on the tubular extension. Thus, it will be appreciatedthat by arranging the spring 56 as illustrated, downward movement of thevalve member 41 and the tubular extension 44 by the elongated rod 43will be effective for compressing the spring. Accordingly, once thestout spring 50 has returned the elongated rod 43 and the valve member41 to their respective elevated positions, the lighter spring 56 will beeffective for retaining the valve member in its elevated position Itwill be appreciated that by virtue of the longitudinal spacing that isnormally present between the shoulder 54 and the ring 52, the rod 43 isfree to travel downwardly a short distance and without significantrestraint before encountering the upwardly-acting forces of the springs50 and 56. This will, therefore, as-

sure that the fluid-impingement :surface 46 is moved well into the mainflow stream of the drilling fluid passing through the ports 38 beforethe ring 52 is engaged so that the fluid-impingement forces acting onthe rod 43 will then be effective for carrying it further downwardlyagainst the increasing upwardly acting spring forces imposed on the rod]by the compression springs 50 and 56.

To initiate the operation of the valve member 41, the pressure-signalingmeans 20 also include a solenoid 58 which is mounted within the innermember 22 and operatively arranged for shifting the rod 43 downwardly atleast as far as is necessary for the fluidimpingement surface 46 to bemoved into the flow path of the drilling fluid passing through the ports38. In the preferred manner of operatively coupling the solenoid 58 tothe elongated rod 43, the axially movable armature or plunger 59 of thesolenoid is adapted to move downwardly upon energization of thesolenoid; and, as depicted in FIG. 4, move the upper end of theelongated rod downwardly a sufficient distance to position thefluid-impinging surface 46 in the flow stream of the drilling fluidpassing through the ports 38. A diaphragm 60 is arranged across thesolenoid plunger 59 to permit the solenoid 58 to be enclosed in oil orthe like.

It will be recognized, of course, that by virtue of the streamlinedconfiguration of the enlarged head 45, downward movement of theelongated rod 43 will require only a minimum force so as to make itunnecessary for the solenoid 58 to be either of significant physicalsize or require excessive power for its operation. As previously noted,once the fluid-impinging surface 46 has entered the main flow stream ofthe drilling fluid passing through the ports 38, the aforementionedcontinued downward travel of the elongated rod 43 will be accomplishedby the impingement and pressure surge forces developed by this fluiduntil the valve member 41 has closed the fluid ports.

As shown in FIG. 6, it will be appreciated that an upright solenoidarmature 59 can alternatively be tandemly mounted on the upper end ofthe elongated rod 43 and operatively arranged in relation to an annularsolenoid coil 58 for shifting the rod downwardly as required to bringthe fluid-impinging surface 46 (not shown in FIG. 6) into the stream ofthe drilling fluid flowing through the ports 38. Then, once theimpingement of the drilling fluid urges the elongated rod furtherdownwardly, the armature 59 mounted on the upper end of the rod 43 maywell be moved entirely below the solenoid coil 58'.

In any event, it should be noted that the solenoid 58 (or 58') needsonly to be capable of shifting the elongated rod 43 downwardly arelatively short distance and that this downward movement requires onlythe minimal force necessary to compress the light spring 55. MOreover,with either of these alternative arrangements of the solenoids 58 and58', should the valve member 41 accidentally become jammed in the valveseat 39 by debris or the like lodged in the ports 38, subsequentapplication of power to the solenoid will not damage it. It is,therefore, of significance to the present invention to realize that themotivating forces supplied by either of the solenoids 58 and 58' areonly minimal since the substantial impingement and pressure forcesimposed on the surface 46 are fully capable of closing the valve member41 once the impingement surface is shifted into the flow stream of thedrilling fluid passing through the ports 38.

Referring again to FIGS. 1 and 2, once the well tool 10 is in positionwithin the borehole 13, the measuring devices 17 and 18 will function toprovide measurements of the particular conditions which are beingmonitored and cause the measurement encoder 19 to produce the series ofelectrical signals representative of these conditions. Each of thesesignals will, therefore, momentarily energize the solenoid 58 toinitiate operation of the pressure-signaling means 20 as in FIGS. 3 and4. Thus, each time the solenoid 58 is energized, the elongated rod 43will be shifted downwardly so as to bring the fluid-impingement surface46 into the stream of the drilling fluid passing through the ports 38.Then, as depicted in FIG. 5, the downwardly acting forces imposed on theimpingement surface 46 by the drilling fluid will carry the elongatedrod 43 further downwardly for shifting the valve member 41 intomomentary seating engagement within the valve seat 39 as well as forsimultaneously compressing the springs 50 and 56. Once the springs 50and 56 are energized, the elongated rod 43 and the valve member 41 willbe returned to their initial elevated positions as depicted in FIG. 3.

To understand the underlying principle of the operation of thepressure-signaling means 20, reference should be made to FIG. 4. At thispoint in the sequence, the enlarged head 45 has just moved into thelongitudinal bore 40 just below the valve seat 39. This movement will,of course, significantly interrupt the downward flow of the circulatingdrilling fluid to produce a substantial positive dynamic pressure whichis imposed on the impingement surface 46. At the same time, thecontinued flow of the drilling fluid that is then below the enlargedhead 45 will simultaneously produce a reduced pressure in thelongitudinal bore 40 below the head. As a result, a substantialdownwardly acting pressure force will be imposed on the surface 46 todrive the elongated rod 43 further downwardly to shift the valve member41 to its port-closing position (FIG. 6). It will, of course, beappreciated that this downwardly-acting pressure force will be equal tothe pressure differential imposed on the effective crosssectional areaof the surface 46.

As the rod 43 and the valve member 41 are driven downwardly, the springs50 and 56 will, of course, be compressed to develop correspondingupwardly acting spring forces tending to return the members to theirrespective elevated positions. Once the valve member 41 closes the ports38, the impingement surface 46 will be isolated from the aforementionedpositive pressure forces. Thus, once the positive pressure in thelongitudinal bore 42 above the enlarged head 45 has been reduced so asto be equalized with the pressure below the head (by way of the passages42 and the narrow clearance space around the head and the adjacent wallof the inner member 22), the spring force provided by the now-compressedspring 50 will be effective for driving the elongated rod 43 upwardly.This upward travel of the rod 43 will, therefore, reposition theenlarged head 45 in the counterbore 47 and then shift the valve member41 upwardly as the elongated rod is returned to its initial elevatedposition by the spring 50.

It will be appreciated, therefore, that each time the solenoid 58 (or59') is energized, the valve member 41 will be rapidly closed and thenquickly reopened so as to produce a momentary pressure surge withoutunduly retarding the continued circulation of the drilling fluid. Aspreviously mentioned, the pressure pulses which are sequentiallyproduced by the repetitive closing and opening of the valve member 41will be transmitted to the surface by way of the stream of drillingfluid being circulated downwardly through the drill string 11. Thus, asthese pressure pulses sequentially arrive at the surface, the surfaceapparatus 21 will detect them to produce a meaningful record which isindicative of the conditions being monitored by the condition-responsivedevices 17 and 18.

Turning now to FIG. 7, the intermediate portion of a well tool is shownto illustrate an alternative embodiment of pressure-signaling means 101which broadly incorporate the principles of the present invention. Asdepicted, the well tool 100 includes a tubular inner member 102 which iscoaxially arranged within an outer tubular housing 103. Although theinner member 102 could be releasably secured to the outer housing 103 ina manner similar to that previously described with reference to the welltoo] 10, it is preferred to permanently mount the inner member withinthe housing as illustrated.

Although it is not illustrated, the upper portion of the well tool 100is arranged in a similar fashion to the well tool 10 and carries aturbine-driven electrical generator (not shown) which is driven by thecontinuous circulation of the drilling fluid passing from the drillstring 11 into the upper end of the well tool 100. The well tool 100 iscooperatively arranged with either oneor more longitudinal passages orthe annular space 104 between the inner and outer members 102 and 103through which the drilling fluid will pass after leaving theturbine-generator (not shown) thereabove. In either case, the downwardlyflowing drilling fluid is directed into one or more downwardly inclinedports 105 arranged near the lowerend of the inner member.

The pressure-signaling means 101 include a valve member 106 coaxiallymounted within the inner member 102 and adapted for axial movementtherein between an elevated position as depicted in FIG. 7 and aport-closing position where the valve member is cooperatively receivedwithin the upper end of a tubular valve seat 107. As will subsequentlybe explained, the valve seat 107 is slidably mounted in the inner member102 and normally retained in its depicted elevated position by biasingmeans such as a compression spring 108 supported on an inwardly directedshoulder 109 on the outer housing 103 and engaged with the lower end ofthe valve seat. To support the valve member 106 for reciprocatingmovement within the inner member 102, an upright extension or rod 110 issecured to the valve member and extended upwardly through an annularguide 111 arranged thereabove within the inner member 102. Biasingmeans, such asa compression spring 1 12 compressed between the guide 111and the valve member 106, are operatively arranged for urging the valvemember downwardly toward its port-closing position.

To releasably retain the valve member 106 in its elevated position,latching means are provided such as one or more upright leaf springs oryieldable fingers 113 which are secured within the inner member 102 andreleasably coupled to the rod 110 by inwardly directed lugs as at 114 onthe mid-portion of each finger which are adapted to remain engaged underone or more outwardly enlarged shoulders 11S spaced along the upperportion of the elongated rod so long as the fingers are retained intheir respective inwardly contracted positions illustrated in FIG. 7. Toretain the fingers 113 in their latching positions, a solenoid 116 iscoaxially mounted within the inner member 102 and includes a verticallyreciprocating armature 117 carrying a downwardly opening cup-like member118 which is adapted for movement between an elevated position above thelatch fingers and the lower position depicted in FIG. 7 wherein the cupat least partially encloses the upper ends of the fingers.

In the preferred embodiment illustrated, upwardly directed wedge-shapedheads, as at 119, are mounted on the upper ends of each of the severalfingers 113 and an annular ring 120 is arranged around the cup 118 todefine an internal downwardly directed wedge-like surface 121 which iscomplemental to the opposed sur faces of the wedge-shaped heads. Thus,so long as the cup 118 is disposed over the upright fingers 113, thering 120 will cooperatively engage the wedgeshaped heads 119 to restrainthe fingers against moving outwardly from their respective positionsshown in FIG. 7. In this manner, so long as the fingers 113 are retainedfrom moving outwardly, the inwardly directed lugs 114 will be maintainedin coengagement under one of the enlarged shoulders 115 on the elongatedrod 110. It will, therefore, be recognized that the spring 112 is urgingthe valve member 106 and the rod 110 downwardly and that it is only thecoaction of the lugs 114 under the shoulder 115 which maintains thevalve member in its elevated position.

On the other hand, as will subsequently be described in further detail,it will be appreciated that once the solenoid 116 is energized towithdraw the cup 1 18 from over the enlarged heads 119, the cooperativecamming action between the enlarged shoulder 115 and the inwardlydirected lugs 114 will be effective for momentarily springing thefingers 113 outwardly to free the elongated rod 110 and the valve member106 for downward movement. Thus, once the solenoid 116 is energized, thecompression spring 112 will be effective for forcefully driving thevalve member 106 downwardly once the enlarged shoulder 115 has expandedthe mid-portions of the fingers 113 sufficiently to disengage theenlarged shoulder from the inwardly directed lugs 114.

Accordingly, as depicted in FIG. 8, once the valve member 106 enters thevalve seat 107, the circulating drilling fluid will be momentarilyhalted so as to produce a transitory pressure surge or pressure pulse inthe nature of a water hammer. THose skilled in the art will, of course,appreciate that the dynamic pressures produced by such water hammers arequite substantial. Thus, by virtue of the rapid movement of the valvemember 106 into seating engagement within the valve seat 107, thesubstantial dynamic pressure force which is developed will be imposed onthe upper end 122 of the valve seat and will be effective for urging thevalve seat downwardly in relation to the outer housing 103.

In view of the substantial magnitude of this pressure force acting onthe effective cross-sectional area of the upper end 122 of the valveseat 107, the valve seat will be shifted downwardly to begin compressingthe spring 109. This same dynamic force will also be imposed on theupper face of the valve member 106 to also move it downwardly into thevalve seat 107.

It will be noted from FIG. 9 that as the valve seat 107 begins movingdownwardly, the valve member 106 will be abruptly halted as an enlargedshoulder 123 on the elongated rod 110 engages the guide 111. Thus, thedynamic pressure force imposed on the upper end 122 of the valve seat107 will be effective for shifting the valve seat away from and out ofengagement with the momentarily halted valve member 106. Moreover, oncethe valve seat 107 is withdrawn from over the valve member 107 asdepicted in FIG. 10 to equalize the pressure differential, a spring 124arranged between the guide 111 and the shoulder 123 will now have beencompressed so as to quickly return the valve member and the elongatedrod 110 upwardly toward their initial elevated positions.

During this same time interval, it will be noted by comparison of FIGS.9 and 10 that the solenoid 116 has now been deenergized so as toreposition the cup 118 back over the enlarged heads 119 of the latchfingers 113. Thus, once the upper ends 119 of the fingers 113 are againreconfined, it will be appreciated that as the enlarged shoulders on theelongated rod 110 move upwardly past the inwardly directed lugs 114, themidportions of the fingers will be momentarily cammed outwardly. Then,once one or more of the shoulders 115 are above the lugs 114, themid-portions of the fingers 113 will again contract to resecure theelongated rod 110 and the valve member 106 in their elevated positionsas depicted in FIG. 7. Similarly, the downwardly-acting dynamic pressureforces acting on the valve seat 107 will be quickly terminated as thevalve member 106 is withdrawn therefrom so that the compression spring124 will rapidly return the valve seat upwardly to its elevated positionas illustrated in FIG. 7.

Accordingly, it will be appreciated that the new and improveddata-signaling apparatus of the present invention is particularlyadapted for producing pressure pulses which are selectively coded fortransmitting information through the drilling fluiid from a borehole tothe surface. To produce these pressure pulses, an electrically operatedactuator is operatively arranged for initiating the operation of valvemeans which, once initiated, employ the circulating drilling fluid as amotive force for operating the valve means.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects; and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. Apparatus adapted for transmitting data to the surface during thedrilling of a borehole and comprising: a tubular drill string having aborehole-drilling device dependently coupled thereto and defining a flowpassage for circulating drilling fluids between the surface and saidborehole-drilling device; data-signaling means on said drill stringadapted for producing electrical signals indicative of at least onedownhole condition; and pressure-signalling means on said drill stringadapted for producing pressure pulses in drilling fluids flowing throughsaid drill string which are representative of the electrical signalsproduced by said datasignaling means, said pressure-signaling meansincluding valve means adapted for movement between a passage-openingposition and a passage-obstructing position for obstructing the flow ofdrilling fluids through said flow passage, a valve actuator adapted formovement between an inactive position and first and second spacedpositions in said flow passage, said valve actuator having afluid-impingement surface thereon adapted to be moved into the path ofdrilling fluids passing through said flow passage upon movement of saidvalve actuator to its said first position and operatively arranged forutilizing such fluids for carrying said valve actuator to its saidsecond position, means on said valve actuator operatively arranged toengage said valve means only after said valve actuator is moved to itssaid first position and then shift said valve means to saidpassage-obstructing position as said valve actuator is carried to itssaid second position, first means responsive to said electrical signalsadapted for moving said valve actuator to its said first position, andsecond means adapted for returning said valve actuator to its saidinactive position and returning said valve means to said passage-openingposition.

2. The apparatus of claim 1 further including means adapted to belocated at the surface and responsive to said pressure pulsestransmitted to the surface for providing indications of said pressurepulses.

3. The apparatus of claim 1 wherein said first means include anelectrical solenoid coupled to said datasignaling means operativelyassociated with said valve actuator and adapted for initiating movementthereof to its said first position upon energization of said solenoid bysaid data-signaling means.

4. The apparatus of claim 1 wherein said second means include meansadapted for reducing pressure differentials across said valve meansafter said valve means are in said passage-obstructing position, andbiasing means operable only upon movement of said valve actuator to itssaid second position for returning said valve actuator to its saidinactive position and returning said valve means to said passage-openingposition once such pressure differentials across said valve means arereduced.

5. Apparatus adapted for transmitting data to the surface during thedrilling of a borehole and comprising: a body adapted for connection ina tubular drill string and having a flow passage arranged to carrydrilling fluids between the surface and a boreholedrilling devicedependently coupled therebelow; and pressure-signaling means on saidbody and including means defining a valve seat in said flow passage, anannular valve member operatively arranged in said flow passage andadapted for longitudinal movement into and out of engagement with saidvalve seat, a valve actuator coaxially arranged within said valve memberand operatively adapted for longitudinal movement in relation to saidbody and said valve member between first and second spaced positions onopposite sides of said valve seat, an enlarged portion on said valveactuator adapted to pass through said valve seat as said valve actuatoris moved between its said first and second positions, means on saidenlarged portion defining a fluidimpingement surface adapted to bestruck by drilling fluids entering said valve seat once said valveactuator is moved away from it said first position and operativelyarranged for such fluids to carry said valve actuator on to its saidsecond position, electrical means operable in response to electricalsignals for initiating movement of said valve actuator away from itssaid first position, first means on said valve actuator adapted toengage said valve member after said valve actuator has moved away fromits said first position and operatively arranged for carrying said valvemember into engagement with said valve seat as said valve actuator ismoved to its said second position, and second means operatively arrangedfor returning said valve actuator to its said first position andcarrying said valve member out of engagement with said valve seat.

6. The apparatus of claim 5 wherein said second means include baisingmeans operative only upon movement of said valve actuator to its saidsecond position for returning said valve actuator to its said firstposition, and means on said valve actuator adapted to engage said valvemember as said valve actuator is returned toward its said first positionfor carrying said valve member out of engagement with said valve seat bythe time that said valve actuator reaches its said first position.

7. The apparatus of claim 5 wherein said second means include meansadapted for reducing pressure differentials across said valve memberonce said valve member is engaged with said valve seat, and biasingmeans operative only upon movement of said valve actuator to its saidsecond position for returning said valve actuator to its said firstposition once such pressure differentials across said valve member arereduced, and means on said valve actuator adapted to engage said valvemember as said valve member is returned toward its said first positionfor carrying said valve member out of engagement with said valve seat bythe time that said valve actuator reaches its said first position.

8. The apparatus of claim 7 further including second biasing meansadapted for retaining said fluid-impingement surface against said valvemember while said valve actuator is in its said first position and saidvalve member is disengaged from said valve seat.

9. Apparatus adapted for determining at least one downhole conditionwhile excavating a borehole and comprising: a tubular drill stringhaving a borehole-excavating device dependently coupled thereto andadapted for circulating drilling fluids between the surface and saidborehole-excavating device; data-signaling means on said drill stringadapted for producing electrical signals indicative of at least onedownhole condition; and pressure-signaling means adapted for developingpressure pulses in drilling fluids flowing through said drill string fortransmission through such fluids to the surface and including firstmeans coupled in said drill string and defining a fluid passage forconducting drilling fluids between said drill string and saidborehole-excavating device, second means movably arranged on said firstmeans for movement between a normal position away from said flow passageand an operating position in said flow passage, third means movablyarranged on said first means for movement between a normal positionallowing flow of drilling fluids through said flow passage and anoperating position for cooperating 'with one of said first and secondmeans to temporarily retard flow of drilling fluids through said flowpassage for producing said pressure pulses, actuating means includingelectrical means operable in response to said electrical signals forselectively moving said second means away from its said normal position,fluid-responsive means operatively arranged on one of said movable meansfor cooperatively moving said one movable means from one of its saidpositions to the other of its said positions, and biasing meansresponsive only after movement of said one movable means from its saidone position for respectively returning said second and third movablemeans to their said normal positions.

10. The apparatus of claim 9 further including means adapted to belocated at the surface and responsive to said pressure pulsestransmitted to the surface for providing indications of said pressurepulses.

lll. Apparatus adapted for determining at least one downhole conditionwhile excavating a borehole and comprising: a tubular drill stringhaving a borehole-excavating device dependently coupled thereto anddefining a flow passage for circulating drilling fluids between thesurface and said borehole-excavating device; data-signaling means onsaid drill string adapted for producing electrical signals indicative ofat least one downhole condition; and pressure-signaling means on saiddrill string adapted for selectively developing pressure pulses indrilling fluids flowing through said fluid passage for transmissionthrough said drill string to the surface and including valve meansadapted for reciprocating movement between passageopening andpassage-closing positions in said fluid passage, fluid-obstructing meansadapted for reciprocating movement back and forth between an inactiveposition and an active position obstructing said fluid passage, meanscooperatively arranged between said fluid-obstructing means and saidvalve means and adapted for moving said valve means to saidpassageclosing position only upon movement of said fluid-obstructingmeans to said active position for producing said pressure pulses,electrical means operable in response to said electrical signals forselectively initiating movement of said fluid-obstructing means towardsaid active position, fluid-responsive means operatively arranged onsaid fluid-obstructing means and operable only upon movement thereofaway from said inactive position for utilizing drilling fluids flowingthrough said fluid passage to move said fluid-obstructing means to saidactive position, first biasing means responsive only to movement of saidfluid-obstructing means to said active position for then returning saidfluid-obstructing means to said inactive position, and second biasingmeans responsive only to movement of said valve means to saidpassage-closing position for then return ing said valve means to saidpassage-opening position.

12. The apparatus of claim 11 further including means adapted to belocated at the surface and responsive to said pressure pulsestransmitted to the surface for providing indications of said pressurepulses.

1. Apparatus adapted for transmitting data to the surface during thedrilling of a borehole and comprising: a tubular drill string having aborehole-drilling device dependently coupled thereto and defining a flowpassage for circulating drilling fluids between the surface and saidborehole-drilling device; data-signaling means on said drill stringadapted for producing electrical signals indicative of at least onedownhole condition; and pressure-signalling means on said drill stringadapted for producing pressure pulses in drilling fluids flowing throughsaid drill string which are representative of the electrical sIgnalsproduced by said data-signaling means, said pressure-signaling meansincluding valve means adapted for movement between a passage-openingposition and a passage-obstructing position for obstructing the flow ofdrilling fluids through said flow passage, a valve actuator adapted formovement between an inactive position and first and second spacedpositions in said flow passage, said valve actuator having afluid-impingement surface thereon adapted to be moved into the path ofdrilling fluids passing through said flow passage upon movement of saidvalve actuator to its said first position and operatively arranged forutilizing such fluids for carrying said valve actuator to its saidsecond position, means on said valve actuator operatively arranged toengage said valve means only after said valve actuator is moved to itssaid first position and then shift said valve means to saidpassage-obstructing position as said valve actuator is carried to itssaid second position, first means responsive to said electrical signalsadapted for moving said valve actuator to its said first position, andsecond means adapted for returning said valve actuator to its saidinactive position and returning said valve means to said passageopeningposition.
 2. The apparatus of claim 1 further including means adapted tobe located at the surface and responsive to said pressure pulsestransmitted to the surface for providing indications of said pressurepulses.
 3. The apparatus of claim 1 wherein said first means include anelectrical solenoid coupled to said data-signaling means operativelyassociated with said valve actuator and adapted for initiating movementthereof to its said first position upon energization of said solenoid bysaid data-signaling means.
 4. The apparatus of claim 1 wherein saidsecond means include means adapted for reducing pressure differentialsacross said valve means after said valve means are in saidpassage-obstructing position, and biasing means operable only uponmovement of said valve actuator to its said second position forreturning said valve actuator to its said inactive position andreturning said valve means to said passage-opening position once suchpressure differentials across said valve means are reduced.
 5. Apparatusadapted for transmitting data to the surface during the drilling of aborehole and comprising: a body adapted for connection in a tubulardrill string and having a flow passage arranged to carry drilling fluidsbetween the surface and a borehole-drilling device dependently coupledtherebelow; and pressure-signaling means on said body and includingmeans defining a valve seat in said flow passage, an annular valvemember operatively arranged in said flow passage and adapted forlongitudinal movement into and out of engagement with said valve seat, avalve actuator coaxially arranged within said valve member andoperatively adapted for longitudinal movement in relation to said bodyand said valve member between first and second spaced positions onopposite sides of said valve seat, an enlarged portion on said valveactuator adapted to pass through said valve seat as said valve actuatoris moved between its said first and second positions, means on saidenlarged portion defining a fluid-impingement surface adapted to bestruck by drilling fluids entering said valve seat once said valveactuator is moved away from it said first position and operativelyarranged for such fluids to carry said valve actuator on to its saidsecond position, electrical means operable in response to electricalsignals for initiating movement of said valve actuator away from itssaid first position, first means on said valve actuator adapted toengage said valve member after said valve actuator has moved away fromits said first position and operatively arranged for carrying said valvemember into engagement with said valve seat as said valve actuator ismoved to its said second position, and second means operatively arrangedfor returning said valve actuator tO its said first position andcarrying said valve member out of engagement with said valve seat. 6.The apparatus of claim 5 wherein said second means include baising meansoperative only upon movement of said valve actuator to its said secondposition for returning said valve actuator to its said first position,and means on said valve actuator adapted to engage said valve member assaid valve actuator is returned toward its said first position forcarrying said valve member out of engagement with said valve seat by thetime that said valve actuator reaches its said first position.
 7. Theapparatus of claim 5 wherein said second means include means adapted forreducing pressure differentials across said valve member once said valvemember is engaged with said valve seat, and biasing means operative onlyupon movement of said valve actuator to its said second position forreturning said valve actuator to its said first position once suchpressure differentials across said valve member are reduced, and meanson said valve actuator adapted to engage said valve member as said valvemember is returned toward its said first position for carrying saidvalve member out of engagement with said valve seat by the time thatsaid valve actuator reaches its said first position.
 8. The apparatus ofclaim 7 further including second biasing means adapted for retainingsaid fluid-impingement surface against said valve member while saidvalve actuator is in its said first position and said valve member isdisengaged from said valve seat.
 9. Apparatus adapted for determining atleast one downhole condition while excavating a borehole and comprising:a tubular drill string having a borehole-excavating device dependentlycoupled thereto and adapted for circulating drilling fluids between thesurface and said borehole-excavating device; data-signaling means onsaid drill string adapted for producing electrical signals indicative ofat least one downhole condition; and pressure-signaling means adaptedfor developing pressure pulses in drilling fluids flowing through saiddrill string for transmission through such fluids to the surface andincluding first means coupled in said drill string and defining a fluidpassage for conducting drilling fluids between said drill string andsaid borehole-excavating device, second means movably arranged on saidfirst means for movement between a normal position away from said flowpassage and an operating position in said flow passage, third meansmovably arranged on said first means for movement between a normalposition allowing flow of drilling fluids through said flow passage andan operating position for cooperating with one of said first and secondmeans to temporarily retard flow of drilling fluids through said flowpassage for producing said pressure pulses, actuating means includingelectrical means operable in response to said electrical signals forselectively moving said second means away from its said normal position,fluid-responsive means operatively arranged on one of said movable meansfor cooperatively moving said one movable means from one of its saidpositions to the other of its said positions, and biasing meansresponsive only after movement of said one movable means from its saidone position for respectively returning said second and third movablemeans to their said normal positions.
 10. The apparatus of claim 9further including means adapted to be located at the surface andresponsive to said pressure pulses transmitted to the surface forproviding indications of said pressure pulses.
 11. Apparatus adapted fordetermining at least one downhole condition while excavating a boreholeand comprising: a tubular drill string having a borehole-excavatingdevice dependently coupled thereto and defining a flow passage forcirculating drilling fluids between the surface and saidborehole-excavating device; data-signaling means on said drill stringadapted for producing electrical signals indicative of at least onedownhole condItion; and pressure-signaling means on said drill stringadapted for selectively developing pressure pulses in drilling fluidsflowing through said fluid passage for transmission through said drillstring to the surface and including valve means adapted forreciprocating movement between passage-opening and passage-closingpositions in said fluid passage, fluid-obstructing means adapted forreciprocating movement back and forth between an inactive position andan active position obstructing said fluid passage, means cooperativelyarranged between said fluid-obstructing means and said valve means andadapted for moving said valve means to said passage-closing positiononly upon movement of said fluid-obstructing means to said activeposition for producing said pressure pulses, electrical means operablein response to said electrical signals for selectively initiatingmovement of said fluid-obstructing means toward said active position,fluid-responsive means operatively arranged on said fluid-obstructingmeans and operable only upon movement thereof away from said inactiveposition for utilizing drilling fluids flowing through said fluidpassage to move said fluid-obstructing means to said active position,first biasing means responsive only to movement of saidfluid-obstructing means to said active position for then returning saidfluid-obstructing means to said inactive position, and second biasingmeans responsive only to movement of said valve means to saidpassage-closing position for then returning said valve means to saidpassage-opening position.
 12. The apparatus of claim 11 furtherincluding means adapted to be located at the surface and responsive tosaid pressure pulses transmitted to the surface for providingindications of said pressure pulses.